Brad Keselowski fretful about next eight days

• Sunday's race at Kansas Speedway and next week's race at Martinsville Speedway key in the Chase
• Jeff Gordon says the driver-crew chief dynamic is going to be crucial in the Hollywood Casino 400
• Five-time champion Jimmie Johnson has been there, done that; isn't worried

KANSAS CITY, Kan. — The next eight days could determine whether points leader Brad Keselowski will raise the NASCAR Sprint Cup championship trophy next month.

Sunday's race at repaved Kansas Speedway has drivers concerned about passing, meaning crew-chief decisions could determine the outcome. Martinsville Speedway, site of next week's seventh of 10 Chase races, ruined Keselowski's title hopes last year with a chain-reaction, late-race spin.

"I think this week and next week are probably going to be two of the toughest weeks for my team," said Keselowski, who leads Jimmie Johnson by seven points, Denny Hamlin by 15 and Clint Bowyer by 28.

"(Kansas) has been very good to me in the past, but obviously it's much different now with the repave. It's hard to exactly know what to expect, so you have to draw off of past history and, thankfully, this year we've had a couple of these situations with Pocono (Raceway) and Michigan (International Speedway), and I feel like we've performed respectable at both those tracks."

Respectable ... not sensational.

Keselowski was caught speeding twice on pit road at Pocono in June and finished 18th in the first race on that repaved track.

He was 13th at Michigan in the first race on that repaved surface in June, although he said afterward he thought his car was better than that.

In the 16 races since Michigan, Keselowski has scored 13 top-10 finishes.

Adding to Keselowski's challenge at Kansas is that he qualified 25th. Johnson will start seventh, Hamlin ninth and Bowyer third.

The groove remains narrow on this ultra-fast track where Kasey Kahne won the pole Friday with a track-record lap of 191.360 mph. Passing could be tricky.

Hamlin was hopeful after Saturday's final practice session that drivers might have more room to work with Sunday.

"I think the groove will widened out a little bit," he said. "I think you'll have a two-groove race track but it's going to take a while for that outside line to burn in."

That's why some drivers say this race could be the biggest unknown in the final five of the Chase.

"I think Kansas is much more of a wild card than Martinsville at this point," 10th-place Kevin Harvick said. "You never know what's going to happen"

The key to the race could be what the driver tells a crew chief and what a crew chief ignores, four-time champion Jeff Gordon said.

"If you are, let's say 15th-place, you are going 'Oh the car is doing this, this, or this,'" Gordon said. "A lot of times that is just aerodynamics. You are just not getting the downforce because you are behind on the cars.

"You have to be very careful and the crew chief has to be careful too taking that information and taking it too literally, because sometimes a driver is frustrated out there and you can take that exact same car doing those things and put it right up there in the front in clean air, and that seems to fix three-quarters of your problems."

Johnson thought Sunday's race would be a "big guessing game" because teams did not see much tire wear, thus won't need to change four tires that often.

These types of races, though, are ones in which five-time champion Johnson and crew chief Chad Knaus have excelled in the past.

"I think our experience under pressure situations and at different race tracks helps us," Johnson said. "So we welcome the change and the excitement."